SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe80fcd16d0bd1cc99588aaee6b80f55848fbdd0e0714b53b154d9633f2495fb' 
  AND token = 'ZKvDkan4tXvPCTMDvuLho6tYUaipnIV9cVA1jNu542g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}